Image sensor module, method of manufacturing the same, camera module including the same and electronic device including the camera module

ABSTRACT

An image sensor module may include an image sensor, a variable thickness member and a lens member. The image sensor may include a light receiver configured to receive a light. Further, a driving voltage may be applied to the image sensor. The variable thickness member may be arranged on the image sensor adjacent to the light receiver. Further, the variable thickness member may have a variable thickness along an optical axis of the light in accordance with the driving voltage through the image sensor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 12/361,774, filed on Jan. 29, 2009, now U.S. Pat. No. 8,053,714,which claims priority under 35 U.S.C. §119 from Korean PatentApplication No. 2008-10755 filed on Feb. 1, 2008 in the KoreanIntellectual Property Office (KIPO), the contents of which are hereinincorporated by reference in their entirety.

BACKGROUND

1. Field of the Invention

The present general inventive concept relates to a sensing apparatus, animage sensor module, a method of manufacturing the same, a camera moduleincluding the same, and an electronic device including the cameramodule. More particularly, the present general inventive concept relatesto a sensing apparatus, an image sensor module that may be capable ofautomatically controlling a focus by moving positions of a lens, amethod of manufacturing the image sensor module, a camera moduleincluding the image sensor module, and an electronic device includingthe camera module.

2. Description of the Related Art

Generally, an image sensor module may include an image sensor forconverting optical information into electrical signals. The image sensormay include a charge coupled device image sensor and a CMOS imagesensor. A cellular phone, which may have a camera function as well as acommunication function by installing the image sensor module in thecellular phone, may be widely used.

A recently developed image sensor module may include an automaticfocusing device for moving positions of a lens to align an opticallength of the lens with a focusing distance, thereby obtaining a cleardisplay. A camera module including the automatic focusing device maychange a focusing distance in accordance with a distance between anobject and an image sensor module to have a wide distance range withrespect to the object. Particularly, a wafer level image sensor modulemay have been developed. The wafer level image sensor module may bemanufactured by stacking an image sensor wafer and a lens wafer, andcutting the image sensor wafer and the lens wafer to form a plurality ofimage sensor modules.

However, in the conventional wafer level image sensor module, anattachment clearance between the image sensor wafer and the lens wafermay be generated. Thus, the image sensor module may be determined to beabnormal due to the attachment clearance, so that a product yield of theimage sensor module may be remarkably reduced.

Further, the conventional automatic focusing device may be mechanicallydriven. When the mechanically driven automatic focusing device may beapplied to the wafer level image sensor module, the image sensor modulemay have a complicated structure and a heavy weight.

SUMMARY

The present general inventive concept provides a sensing apparatus, forexample, an image sensor module that may be capable of being applied toa wafer level camera module and having a slim structure and an automaticfocusing function.

The present general inventive concept also provides a method ofmanufacturing the above-mentioned image sensor module.

The present general inventive concept still also provides a cameramodule including the above-mentioned image sensor module.

The present general inventive concept yet still also provides anelectronic device including the above-mentioned camera device.

Additional aspects and utilities of the present general inventiveconcept will be set forth in part in the description which follows and,in part, will be obvious from the description, or may be learned bypractice of the general inventive concept.

The foregoing and/or other aspects and utilities of the present generalinventive concept may be achieved by providing an image sensor module.The image sensor module may include an image sensor, a variablethickness member and a lens member. The image sensor may include a lightreceiver configured to receive a light. Further, a driving voltage maybe applied to the image sensor. The variable thickness member may bearranged on the image sensor adjacent to the light receiver. Further,the variable thickness member may have a variable thickness along anoptical axis of the light in accordance with the driving voltage throughthe image sensor. The lens member may be arranged on the variablethickness member. The lens member may be moved along the optical axis inaccordance with the thickness of the variable thickness member.

The image sensor may include a substrate, at least one externalterminal, at least one bonding pad and at least one electrode. The lightreceiver may be formed on the substrate. The external terminal may beformed on a first surface of the substrate to receive the drivingvoltage. The bonding pad may be formed on an edge portion of a secondsurface of the substrate opposite to the first surface. The boding padmay be electrically connected to the variable thickness member. Theelectrode may penetrate the edge portion of the substrate toelectrically connect between the external terminal and the bonding pad.

The variable thickness member may have an annular shape configured tocover the bonding pad. Further, the variable thickness member mayinclude a conductive polymer of which a volume may vary in accordancewith the driving voltage. The conductive polymer may include apiezoelectric material.

The foregoing and/or other aspects and utilities of the present generalinventive concept may also be achieved by providing a method ofmanufacturing an image sensor module. In the method of manufacturing theimage sensor module, an image sensor wafer including at least one imagesensor and a bonding pad may be prepared. The bonding pad may bearranged on an edge portion of the image sensor to receive a drivingvoltage. A variable thickness member may be attached to the image sensorwafer. The variable thickness member may have a variable thickness inaccordance with the driving voltage. A lens wafer including at least onelens layer may be formed on the variable thickness member.

The image sensor wafer may be prepared by forming the image sensor on asubstrate, forming the bonding pad on an edge portion of the substrate,and forming an electrode through the edge portion of the substrate to beelectrically connected with the bonding pad. Further, a thermocompression bonding process may be performed on the edge portion of thesubstrate to attach the variable thickness member to the edge portion ofthe substrate.

Alternatively, an ultraviolet curing process may be performed on theedge portion of the substrate to attach the variable thickness member tothe edge portion of the substrate. The variable thickness member mayinclude a conductive polymer of which a volume may vary in accordancewith the driving voltage. The conductive polymer may include apiezoelectric material.

The image sensor wafer may include a plurality of the image sensors.Further, the lens wafer may include the single lens layer. In this case,the method may further include cutting the image sensor wafer and thelens wafer to form a plurality of the image sensor modules. Each of theimage sensor modules may include the single image sensor and the singlelens layer.

The foregoing and/or other aspects and utilities of the present generalinventive concept may also be achieved by providing a camera module. Thecamera module may include a main substrate, an image sensor, a variablethickness member and a lens member. The main substrate may generate adriving voltage. The image sensor may include a light receiverconfigured to receive a light. Further, the driving voltage may beapplied to the image sensor. The variable thickness member may bearranged on the image sensor adjacent to the light receiver. Further,the variable thickness member may have a variable thickness along anoptical axis of the light in accordance with the driving voltage throughthe image sensor. The lens member may be arranged on the variablethickness member. The lens member may be moved along the optical axis inaccordance with the thickness of the variable thickness member.

The camera module may further include a controller arranged on the mainsubstrate to control the driving voltage.

The image sensor may include a substrate, at least one externalterminal, at least one bonding pad and at least one electrode. The lightreceiver may be formed on the substrate. The external terminal may beformed on a first surface of the substrate to receive the drivingvoltage. The bonding pad may be formed on an edge portion of a secondsurface of the substrate opposite to the first surface. The boding padmay be electrically connected to the variable thickness member. Theelectrode may penetrate the edge portion of the substrate toelectrically connect between the external terminal and the bonding pad.

The foregoing and/or other aspects and utilities of the present generalinventive concept may also be achieved by providing an electronicdevice. The electronic device may a camera module, a controlling member,an inputting member and a displaying member. The camera module mayinclude a main substrate, an image sensor, a variable thickness memberand a lens member. The main substrate may generate a driving voltage.

The image sensor may include a light receiver configured to receive alight. Further, the driving voltage may be applied to the image sensor.The variable thickness member may be arranged on the image sensoradjacent to the light receiver. Further, the variable thickness membermay have a variable thickness along an optical axis of the light inaccordance with the driving voltage through the image sensor. The lensmember may be arranged on the variable thickness member. The lens membermay be moved along the optical axis in accordance with the thickness ofthe variable thickness member. The controlling member may apply acontrol signal to the camera module. The inputting member may input acommand into the controlling member. The displaying member may displayan image based on image signals generated from the camera module.

The variable thickness member having the variable thickness inaccordance with the driving voltage may be interposed between the imagesensor and the lens member, so that the image sensor module may have anautomatic focusing function. Further, when an attachment clearance maybe generated between the image sensor and the lens, a distance betweenthe image sensor and the lens may be optimized by applying the drivingvoltage to the variable thickness member, so that a product yield of thewafer level camera module may be significantly improved.

The foregoing and/or other aspects and utilities of the present generalinventive concept may also be achieved by providing a method of formingan image sensor module, the method including forming an image sensorhaving a light receiver and an electrode, forming a lens member disposedto transmit a signal to the light receiver of the image sensor, andforming a variable thickness member between the image sensor and thelens member to control a distance between the image sensor and the lensmember according to a driving signal applied through the electrode ofthe image sensor.

The foregoing and/or other aspects and utilities of the present generalinventive concept may also be achieved by providing a sensor moduleincluding an image sensor having a light receiver and an electrode, alens member disposed to transmit a signal to the light receiver of theimage sensor, and a variable thickness member disposed between the imagesensor and the lens member to control a distance between the imagesensor and the lens member according to a driving signal applied throughthe electrode of the image sensor.

The image sensor may further include a plurality of external terminalsto be connected to the respective ones of the light receiver and theelectrode.

The sensor module may further include an external device having a mainsubstrate formed with a plurality of pads to be connected to therespective external terminals of the image sensor.

The external device may include a unit to perform an operation accordingto data corresponding to the signal of the image sensor.

The image sensor may include a substrate, the light receiver may bedisposed on the substrate, and the electrode may be formed in thesubstrate to be exposed to the variable thickness member to change athickness of the variable thickness member according to the drivingsignal.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and utilities of the present generalinventive concept will become apparent and more readily appreciated fromthe following description of the embodiments, taken in conjunction withthe accompanying drawings of which

FIG. 1 is a cross-sectional view illustrating an image sensor moduleaccording to an embodiment of the present general inventive concept;

FIG. 2 is a plan view illustrating an image sensor of the image sensormodule in FIG. 1;

FIG. 3 is a cross-sectional view illustrating a variable thicknessmember of the image sensor module in FIG. 1;

FIG. 4 is a flow chart illustrating a method of manufacturing an imagesensor module according to an embodiment of the present generalinventive concept;

FIG. 5A is a perspective view illustrating a process to prepare an imagesensor wafer;

FIG. 5B is an enlarged plan view illustrating a portion “A” in FIG. 5A;

FIG. 5C is a cross-sectional view taken along a line I-I′ in FIG. 5B;

FIG. 6A is a cross-sectional view illustrating a variable thicknessmember in accordance with some example embodiments;

FIG. 6B is an enlarged plan view illustrating a portion “B” in FIG. 6A;

FIG. 6C is a cross-sectional view taken along a line II-II′ in FIG. 6B;

FIG. 7A is a perspective view illustrating a process to combine a lenswafer and a variable thickness member according to an embodiment of thepresent general inventive concept;

FIG. 7B is an enlarged plan view illustrating a portion “C” in FIG. 7A;

FIG. 7C is a cross-sectional view taken along a line III-III′ in FIG.7B;

FIG. 8 is a cross-sectional view illustrating a process to cut a lenswafer and an image sensor wafer according to an embodiment of thepresent general inventive concept;

FIG. 9 is a cross-sectional view illustrating a camera according to anembodiment of the present general inventive concept; and

FIG. 10 is a block diagram illustrating an electronic device accordingto an embodiment of the present general inventive concept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentgeneral inventive concept, examples of which are illustrated in theaccompanying drawings, wherein like reference numerals refer to the likeelements throughout. The embodiments are described below in order toexplain the present general inventive concept by referring to thefigures.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numerals refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present general inventive concept.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent general inventive concept. As used herein, the singular forms“a,” “an” and “the” are intended to include the plural forms as well,unless the context clearly indicates otherwise. It will be furtherunderstood that the terms “comprises” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized example embodiments (and intermediate structures). As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, example embodiments should not be construed as limitedto the particular shapes of regions illustrated herein but are toinclude deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofthe present general inventive concept.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this general inventive conceptbelongs. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Hereinafter, example embodiments will be explained in detail withreference to the accompanying drawings.

FIG. 1 is a cross-sectional view illustrating a sensing apparatus, forexample, an image sensor module according to an embodiment of thepresent general inventive concept, FIG. 2 is a plan view illustrating animage sensor of the image sensor module in FIG. 1, and FIG. 3 is across-sectional view illustrating a variable thickness member of theimage sensor module in FIG. 1. The sensing apparatus may be a signalsensing module, a light sensing module, etc. to sense an externalsignal, such as a light beam, corresponding to an object or an image tobe detected. However, the present general inventive concept is notlimited thereto. Other type of a sensing apparatus can be used as thesensing apparatus of the present general inventive concept.

Referring to FIGS. 1 to 3, the image sensor module 100 of this exampleembodiment may include an image sensor 110, a variable thickness member130 and a lens member 140.

The image sensor 110 may convert an optical image into an electricalsignal using a light reflected from an object. In some exampleembodiments, examples of the image sensor 110 may include a chargecoupled device (CCD) image sensor, a complementary metal oxidesemiconductor (CMOS) image sensor, etc. Although not illustrated indrawings, the CMOS image sensor may include a photodiode to sense alight, and a logic circuit to convert the light into an electricalsignal as a unit pixel. Further, the CMOS image sensor may include onephotodiode and four transistors as a unit pixel such that an image canbe detected from the incident light. However, the present generalinventive concept is not limited thereto. Other type of an image sensorcan be used as the image sensor 110 of the present general inventiveconcept. It is also possible that a signal sensor can be used as thesensor of the present general inventive concept to sense an externalsignal transmitted through a transmission element, such as the lensmember 140. Therefore, the variable thickness member 130 can be used tocontrol a distance and/or angle between the image sensor 110 and thelens member 140 such that the external signal, such as the light beam,can be controlled to be detected at the image sensor 110 according to adesired condition of the incident light, electrical signal, and/orsensed image.

In an embodiment, the image sensor 110 may include a substrate 111, anexternal terminal 121, a bonding pad 125 and an electrode 127.

The substrate 111 may include a light receiver 113 formed on a centralupper surface of the substrate 111 to receive a light. The lightreceiver 113 may have the photodiode and the transistors.

The image sensor 110 may further include an electrode (circuit) 113 adisposed inside the substrate 111 to be connected to the light receiver113 to transmit (process) the electrical signal, an external terminal113 b, and a conductive line 113 c formed on the substrate 111 toelectrically connect the electrode or circuit 113 a to the externalterminal 113 b such that the image sensor 110 can communicate with anexternal device. The electrode (circuit) 113 a may be disposed outsidethe substrate 111 to connect the image sensor 110 and the externalterminal 113 b.

The external terminal 121 may be mounted on a first surface of thesubstrate 111. In an embodiment, the first surface of the substrate 111may correspond to a lower surface of the substrate 111. The externalterminal 121 may be electrically connected to the electrode 127. Theexternal terminal 121 may receive a driving voltage from an externaldevice and then transmit the driving voltage to the variable thicknessmember 130 through the electrode 127. The external terminal 121 mayinclude a solder ball.

In an embodiment, the external terminal 121 may further include an underbump metallurgy (UBM) to improve a wettability. The external terminal121 having the UBM may make contact with a solder paste to easily formthe solder ball.

A bonding pad 125 may be arranged on a second surface of the substrate111 opposite to the first surface. That is, the bonding pad 125 may bearranged on an upper surface of the substrate 111. In an embodiment, thebonding pad 125 may be located on an edge portion of the second surfaceof the substrate 111. The bonding pad 125 may make contact with thevariable thickness member 130 to transmit the driving voltage to thevariable thickness member 130.

In an embodiment, the bonding pad 125 may have a rectangular plateshape. Further, the bonding pad 125 may include a conductive metal suchas gold (Au), silver (Ag), copper (Cu), chromium (Cr), aluminum (Al),nickel (Ni), tin or stannum (Sn), lead or plumbum (Pb) or an alloythereof.

In an embodiment, when the substrate 111 has the rectangular plateshape, the bonding pad 125 may be arranged on corners of the substrate111. Thus, the driving voltage may be uniformly applied to the variablethickness member 130 through the bonding pad 125 on the corners of thesubstrate 111.

The electrode 127 may vertically penetrate an edge portion of thesubstrate 111. The electrode 127 may have an upper end to make contactwith the bonding pad 125, and a lower end to make contact with theexternal terminal 121. That is, the bonding pad 125 and the externalterminal 121 may be electrically coupled with each other via theelectrode 127. Thus, the driving voltage may be applied to the variablethickness member 130 through the electrode 127 in the edge portion ofthe substrate 111. It is possible that a wire to transmit the drivingvoltage to the variable thickness member 130 may not be needed in theimage sensor module 100.

In an embodiment, the electrode 127 may include a material substantiallythe same as that of the bonding pad 125. Alternatively, the electrode127 may include a material different from that of the bonding pad 125.The electrode 127 may include a conductive metal such as gold (Au),silver (Ag), copper (Cu), chromium (Cr), aluminum (Al), nickel (Ni),stannum (Sn), plumbum (Pb) or an alloy thereof.

In an embodiment, the image sensor 110 may further include a connectingline 129 formed on the first surface of the substrate 111. Theconnecting line 129 may connect the external terminal 121 to theelectrode 127. The connecting line 129 may extend from a central pad(not illustrated), which may be formed on a central portion of the firstsurface of the substrate 111, toward the electrode 127.

Since a location or length of the connecting line 129 can be changed oradjusted with respect to the electrode 127, a position of the externalterminal 121 can be changed or adjusted with respect to the substrate111. When it is desirable to dispose the external terminal 121 on acertain portion of the substrate 111, the connecting line 129 can beextended from a position of the electrode 127 toward the desiredposition of the substrate 111. Accordingly, an external device having aconnector can be connected to the external terminal 121 according to alocation of the connector thereof.

The variable thickness member 130 may be arranged on the edge portion ofthe image sensor 110. Because the light receiver 113 may be arranged onthe central portion of the image sensor 110, the variable thicknessmember 130 may not be overlapped with the light receiver 113. Thevariable thickness member 130 may have a thickness varying along anoptical axis of the light in accordance with the driving voltage fromthe bonding pad 125 of the image sensor 110. That is, when the drivingvoltage may be applied to the variable thickness member 130, a volume ora phase of the variable thickness member 130 may be changed, so that thethickness of the variable thickness member 130 may also be changed alongthe optical axis.

In an embodiment, the variable thickness member 130 may have an annularshape configured to cover the bonding pad 125. As a result, the lightreceiver 113 may be exposed by the variable thickness member 130 on theedge portion of the image sensor 110.

In an embodiment, referring to FIG. 3, the variable thickness member 130may include a first electrode 131, a second electrode 135 to face thefirst electrode 131, and a conductive polymer layer 133 interposedbetween the first electrode 131 and the second electrode 135. Theconductive polymer layer 133 may include a piezoelectric material. Forexample, when a potential difference may be generated between the firstelectrode 131 and the second electrode 135, a volume or a phase of thepiezoelectric material between the first electrode 131 and the secondelectrode 135 may be changed. Therefore, the thickness of the variablethickness member 130 may vary along an optical axis of the light.

The variable thickness member 130 may be controlled to change athickness with respect to the image sensor 110 and/or the lens member140 in a first direction perpendicular to a second direction of a majorsurface of the light receiver 113 and/or the lens layer 143. The majorsurface may be parallel to the first surface or the second surface ofthe substrate 111. The first direction may be parallel to a lightincident direction in which a light beam is incident to the lightreceiver 113 through the lens member 140.

The variable thickness member 130 may have an area disposed parallel tothe major surface of the light receiver 113 and/or the lens layer 143 ordisposed parallel to the second direction. The entire area of thevariable thickness member 130 may move in the same direction by a samedistance with respect to the image sensor 110 and/or the lens member 140according to the driving signal applied from a controller of anelectronic apparatus to the electrode 127 of the variable thicknessmember 130.

It is possible that the area of the variable thickness member 130 maymove in a direction having an angle with the above describe direction.That is, the area of the variable thickness member 130 may have an anglewith the first direction or the second direction. FIG. 2 illustratesfour bonding pads 125 to correspond to the respective electrodes 127.However, the present general inventive concept is not limited thereto.The number of the electrodes 127 and bonding pads 125 can be more thanfour or can be two. When a first driving voltage (or signal) is appliedto a first combination of the four electrodes 127 and a second drivingvoltage (or signal) is applied to a second combination of the fourelectrodes 127, the thickness of the variable thickness member 130 mayvary according to locations of the first and second combinations of thefour electrodes 127 or according to areas or positions or the bondingpads 125 contacting the variable thickness member 130 such that the lensmember 140 can move in a direction having an angle with respect to thefirst and second directions.

When it is required to move the lens member 140 in a same direction by asame distance with respect to the light receiver 113, a same drivingvoltage (signal) is applied to the four electrodes 127 as the first andsecond driving voltage (signal).

When a first portion of the variable thickness member 130 has a firstcharacteristic different from a second characteristic of a secondportion of the variable thickness member 130 in controlling thethickness, it is possible to apply different driving voltages (signals)to the respective electrodes to obtain a uniform thickness change suchthat the lens member 140 can move in a desired direction with respect tothe light receiver 113.

The above-described thickness change may correspond to a volume changeof the variable thickness member 130. The change of the variablethickness member 130 in thickness or volume may correspond to a changein distance between the image sensor 110 and the lens member 140.

One of the first electrode 131 and the second electrode 135 (FIG. 3) maybe connected to the electrode 127 through the bonding pad 125, and theother one of the first electrode 131 and the second electrode 135 may beconnected to a potential, for example, a ground potential. Therefore, apotential difference between the driving voltage and the potentialgenerate a volume change of the conductive polymer layer 133 such that adistance and angle of the lens member 140 is changed with respect to thelight receiver 113. The one of the first electrode 131 and the secondelectrode 135 may be connected to the electrode 111 without the bondingpad 125. The bonding pad 125 may be disposed in the substrate 127 tocontact the one of the first electrode 131 and the second electrode 135.In this case, the bonding pad 125 may have an outer surface disposed ona plane on which the second surface of the substrate 111 is disposed.The bonding pad 125 and the electrode 127 may be formed in a monolithicconductive body.

The lens member 140 may be arranged on the variable thickness member130. Here, because the lens member 140 may make contact with thevariable thickness member 130, a position of the lens member 140 mayvary in accordance with the variable thickness of the variable thicknessmember 130.

For example, when the thickness of the variable thickness member 130 maybe increased by applying the driving voltage to the variable thicknessmember 130, the lens member 140 may be upwardly moved to increase adistance between an upper surface of the image sensor 110 and the lensmember 140. In contrast, the thickness of the variable thickness member130 may be decreased by suspending the applying of the driving voltageto the variable thickness member 130, the lens member 140 may bedownwardly moved to decrease the distance between the upper surface ofthe image sensor 110 and the lens member 140. Thus, a focus of the imagesensor module 100 may be automatically adjusted until the image sensormodule 100 may have an optimal resolution by changing the distancebetween the lens member 140 and the image sensor 110. As a result, thefocus of the image sensor module 100 may be automatically adjusted byapplying the driving voltage to the variable thickness member 130without an automatic focusing device.

Further, when a wafer level image sensor module may be manufactured byattaching the image sensor 110 to the lens member 140, an attachmentclearance may be generated between the image sensor 110 and the lensmember 140. Although the attachment clearance may be generated betweenthe image sensor 110 and the lens member 140, the driving voltage may beapplied to the variable thickness member 130 to change the thickness ofthe variable thickness member 130. As a result, the distance between theimage sensor 110 and the lens member 140 may be optimally adjusted tocontrol the focus of the image sensor module 100.

In an embodiment, the lens member 140 may include a protecting layer 141and a lens layer 143 formed on the protecting layer 141. Further, thelens member 140 may have a structure where a plurality of the lenslayers 143 may be stacked. For example, the lens member 140 may includethe two lens layers 143. Alternatively, the lens member 140 may includeat least three lens layers 143. Additionally, the lens member 140 mayfurther include an infrared ray blocking film (not illustrated). Theinfrared ray blocking film may filter an infrared ray having a longwavelength in the light incident to the light receiver 113. Further, thelens member 140 may additionally include an anti-reflective film (notillustrated) to suppress a reflection of the light. Alternatively, thelens member 140 may include at least one lens layer 143 without theprotecting layer 141.

In an embodiment, the image sensor module 100 may further include anadhesive member (not illustrated) interposed between the variablethickness member 130 and the image sensor 110 to attach the variablethickness member 130 to the image sensor 110.

A space C can be formed between surfaces of the lens member 140 and theimage sensor 110. The space C may be filled with a material, such as agas with a predetermined pressure. It is also possible that the space Cmay be in a vacuum state or may have a pressure close to the vacuumstate. However, it is possible that the pressure of the space C may be anormal air pressure in a room temperature.

It is possible that an external surface of the light receiver 113 may beon a plane on which the second surface of the substrate 111 is disposed.In this case, at least a portion of the light receiver 113 protrudesfrom the second surface of the substrate 111 toward the space C. it isalso possible that the portion of the light receiver 113 is spaced apartfrom a bottom surface of the lens member 140 by a variable distance whenthe second surface of the substrate 111 is spaced apart from the bottomsurface of the lens member 140 by a second variable distance.

FIG. 4 is a flow chart illustrating a method of manufacturing the imagesensor module in FIG. 1, FIG. 5A is a perspective view illustrating aprocess to prepare an image sensor wafer, FIG. 5B is an enlarged planview illustrating a portion “A” in FIG. 5A, and FIG. 5C is across-sectional view taken along a line I-I′ in FIG. 5B.

Referring to FIGS. 4 and 5A to 5C, in operation S110, an image sensorwafer 211 may be prepared. In an embodiment, the image sensor wafer 211may include a plurality of image sensors 210 and a bonding pad 225. Adriving voltage may be applied to the bonding pad 225.

Further, the image sensor wafer 211 may include a light receiver 213, anelectrode 227 and the bonding pad 225. Additionally, the image sensorwafer 211 may include a data pad and a ground pad formed on an uppersurface of the image sensor wafer 211. A data signal may be applied tothe data pad. A reference voltage may be applied to the ground pad. Thedata pad and the ground pad may be exposed. Thus, to suppress anelectrical connection between the bonding pad 225 and other pads, anadditional process may be performed to selectively expose the bondingpad 225.

In an embodiment, the image sensing wafer 211 may include an electrode213 a as a circuit or a conductive line to be connected to the lightreceiver 213 to transmit or process the data signal of the incidentsignal, such as the light beam signal, and a pad 213 c may be formed onthe image sensing wafer 211 to be electrically connected to theelectrode 213 a.

FIG. 6A is a cross-sectional view illustrating a variable thicknessmember in accordance with some example embodiments, FIG. 6B is anenlarged plan view illustrating a portion “B” in FIG. 6A, and FIG. 6C isa cross-sectional view taken along a line II-II′ in FIG. 6B.

Referring to FIGS. 4 and 6A to 6C, in operation S120, a variablethickness member 230 may be formed on an edge portion of the imagesensor wafer 211. Here, because the light receiver 213 may be placed onthe central portion of the image sensor wafer 211, the variablethickness member 230 may not be overlapped with the light receiver 213.That is, the variable thickness member 230 may be overlapped with thebonding pad 225 and the electrode 227.

In an embodiment, a variable thickness layer (not illustrated) may beformed on the image sensor wafer 211. The variable thickness layer maybe attached to the image sensor wafer 211 by a thermo compressionbonding process or an ultraviolet curing process. In the thermocompression bonding process, the variable thickness layer may becompressed toward the image sensor wafer 211 at a predeterminedtemperature to attach the variable thickness layer to the image sensorwafer 211. In the ultraviolet curing process, an ultraviolet ray may beirradiated to the variable thickness layer to cure the variablethickness layer by a photoreaction of a photo initiator in the variablethickness layer, thereby attaching the variable thickness layer to theimage sensor wafer 211.

A light may then be irradiated to the variable thickness layer using amask to pattern the variable thickness layer, thereby forming thevariable thickness member 230 on the image sensor wafer 211. Thevariable thickness member 230 may be electrically connected to thebonding pad 225.

In an embodiment, the variable thickness member 230 may include aconductive polymer layer such as a piezoelectric material.

FIG. 7A is a perspective view illustrating a process to combine or stacka lens wafer on a variable thickness member according to an embodimentof the present general inventive concept, FIG. 7B is an enlarged planview illustrating a portion “C” in FIG. 7A, and FIG. 7C is across-sectional view taken along a line III-III′ in FIG. 7B.

Referring to FIGS. 4 and 7A to 7C, in operation S130, a lens wafer 240may be stacked on the image sensor wafer 211 having the variablethickness member 230. In some example embodiments, the lens wafer 240may be attached to the image sensor wafer 211 by a thermo compressionbonding process. Further, the lens wafer 240 may include at least onelens layer 214.

In the thermo compression bonding process, an adhesive layer (notillustrated) may be formed on a lower surface of the lens wafer 240. Inan embodiment, the adhesive layer may include a high polymer resin.Further, the adhesive layer may have a latticed structure configured toattach the lens wafer 240 to the image sensor wafer 211. After dicing,the adhesive layer may seal between an image sensor and a lens member inan image sensor module. A heat and a pressure may be applied to theimage sensor wafer 211 and the lens wafer 240. The image sensor wafer211 and the lens wafer 240 may then be post-cured to attach the lenswafer 240 to the image sensor wafer 211.

In an embodiment, a connecting line 229 (FIG. 7C) may be further formedon a lower surface of the image sensor wafer 211. The connecting line229 may be electrically connected to the electrode 227. The connectingline 229 may extend from a central pad (not illustrated) on a centralportion of the image sensor wafer 211 toward the electrode 227.

In an embodiment, a protecting layer 241 may be formed between the lenswafer 240 and the image sensor wafer 211. The protecting layer 241 mayinclude a glass substrate. The protecting layer 241 may protect theimage sensor wafer 211 from foreign substances.

FIG. 8 is a cross-sectional view illustrating a process to cut a lenswafer and an image sensor wafer according to an embodiment of thepresent general inventive concept.

Referring to FIGS. 4 and 8, in operation S140, the image sensor wafer211 and the lens wafer 240 attached to each other may be cut along theadhesive layer to form an image sensor module 200. In some exampleembodiments, the image sensor wafer 211 and the lens wafer 240 may becut using a dicing apparatus having a blade.

Therefore, the image sensor module 200 may include an image sensor 210,the variable thickness member 230 and a lens member 240.

As illustrated in FIG. 8, the image sensing wafer 211 may include anelectrode 213 a as a circuit or a conductive line to be connected to thelight receiver 213 to transmit or process the data signal of theincident signal, such as the light beam signal, a pad 213 c may beformed on the image sensing wafer 211 to be electrically connected tothe electrode 213, and an external terminal 213 b may be formed on thepad 213 c to be connected to an external device.

FIG. 9 is a cross-sectional view illustrating a camera module accordingto an embodiment of the present general inventive concept.

Referring to FIG. 9, the camera module of this example embodiment mayinclude a main substrate 305, an image sensor 310, a variable thicknessmember 330 and a lens member 340.

In an embodiment, the main substrate 305 may include a controller 307 togenerate a driving voltage. The controller 307 may include a digitalsignal processing chip mounted on the main substrate 305. Alternatively,the controller 307 may be built in the image sensor 310. A connectingpad 309 may be mounted on the main substrate 305 to be connected to thecontroller 307. The connecting pad 309 may be electrically connected toan external terminal 321.

In an embodiment, the image sensor 310 may include a substrate 311, atleast one external terminal 321, at least one bonding pad 325 and atleast one electrode 327. The substrate 311 may have a light receiver313. The external terminal 321 may be mounted on a first surface of thesubstrate 311. The driving voltage may be applied to the externalterminal 321. The bonding pad 325 may be formed on a second surface ofthe substrate 311 opposite to the first surface. The bonding pad 325 maybe electrically connected to the variable thickness member 330. Theelectrode 327 may penetrate an edge portion of the substrate 311. Theelectrode 327 may electrically connect the external terminal 321 withthe bonding pad 325 through a pad 329.

The image sensor 310, the variable thickness member 330 and the lensmember 340 may be mounted on the main substrate 305. The image sensor310, the variable thickness member 330 and the lens member 340 may beelectrically connected to the connecting pad 309. Here, the image sensor310, the variable thickness member 330 and the lens member 340 may besubstantially similar to the image sensor 110, the variable thicknessmember 130 and the lens member 140 in FIG. 1, respectively. Thus, anyfurther illustrations with respect to the image sensor 310, the variablethickness member 330 and the lens member 340 are omitted herein forbrevity.

The image sensor module having the variable thickness member 330 may bemounted on the main substrate 305. The image sensor module having thevariable thickness member 330 may function as a mechanical actuator forautomatically controlling a focus of the camera module. Thus, the cameramodule may include the wafer level image sensor module.

As illustrated in FIG. 9, the image sensor 310 may include an electrode313 a formed in the substrate 311 as a circuit or a conductive line tobe connected to the light receiver 313 to transmit or process the datasignal of the incident signal, such as the light beam signal, a pad 313c may be formed on the substrate 311 to be electrically connected to theelectrode 213, and an external terminal 313 b may be formed on the pad313 c to be connected to an external device. Another connecting pad 309a may be formed on the main substrate 305 to be connected to theexternal terminal 313 b.

The pads 329 and 313 c may have a location and a length with respect tothe electrode 327 and 313 a, respectively, so that the connecting pads309 and 309 a can be connected to the respective external terminals 321and 313 b according to a predetermined specification of the image sensorand the main substrate 305. Therefore, the image sensor can easily beconnected to the main substrate 305 using relative positions of theelectrodes 327 and 313 a and the connecting pads 309 and 309 a.

FIG. 10 is a block diagram illustrating an electronic device accordingto an embodiment of the present general inventive concept.

Referring to FIGS. 9 and 10, the electronic device 400 of this exampleembodiment may include a camera module 410, a controlling member 420, aninputting member 430 and a displaying member 440. According to thepresent general inventive concept, the electronic device may include acamera phone. However, the present general inventive concept is notlimited thereto. The electronic device may be an apparatus to detect animage or an object, to process data corresponding to the image orobject, and to perform an operation using the processed data.

The camera module 410 may include the main substrate 305 (See FIG. 9),an image sensor 411, a variable thickness member 412 and a lens member413. The main substrate 305 may generate a driving voltage. The imagesensor 411 may include a light receiver configured to receive a light.The driving voltage may be applied to the image sensor 411. The variablethickness member 412 may be arranged on the image sensor 411 adjacent tothe light receiver. The variable thickness member 412 may have avariable thickness along an optical axis of the light in accordance withthe driving voltage from the image sensor 411. The lens member 413 maybe arranged on the variable thickness member 411. The lens member 413may be moved along the optical axis in accordance with the variablethickness of the variable thickness member 412. Here, the camera module410 may be substantially similar to the camera module in FIG. 9. Thus,any further illustrations with respect to the camera module 410 areomitted herein for brevity.

The controlling member 420 may apply a control signal to the cameramodule. For example, when a use may input an operational command to theelectronic device 400, the controlling member 420 may apply acorresponding control signal to the camera module 420.

The inputting member 430 may include inputting terminals (notillustrated). The user may input a specific command for driving theelectronic device 400 through the inputting terminals. Examples of theinputting terminals may include a key pad, a touch screen, etc., of acommunication device.

The displaying member 440 may display an image using image signalsgenerated from the camera module 410. Examples of the displaying member440 may include a liquid display device (LCD), an organic emittingdevice, etc.

Further, the electronic device 400 may include a communicating member460 to transmit signals between the camera module 410, the controllingmember 420, the inputting member 430 and the displaying member 440 witheach other.

According to an embodiment, the image sensor module having the variablethickness member may function as a mechanical actuator to automaticallycontrol a focus of the camera module. Thus, the camera module mayinclude the wafer level image sensor module. As a result, a smallerelectronic device may be manufactured.

Further, the variable thickness member may have a variable thicknessalong an optical axis of the light in accordance with the drivingvoltage through the image sensor. The lens member may be arranged on thevariable thickness member. The lens member may be moved along theoptical axis in accordance with the thickness of the variable thicknessmember. Thus, a focus of the image sensor module may be automaticallycontrolled.

Further, the image sensor module may be employed in a cellular cameraphone having an automatic focusing device. However, the present generalinventive concept is not limited thereto. An electronic apparatus havinga sensor to detect an external signal, a transmitter to receive andtransmit the external signal, and an electrically controlled member toadjust a distance or angle of the transmitter with respect to the sensorcan be used as the image sensor of the present general inventiveconcept. Furthermore, the image sensor module may be employed in asmall, slim and light camera module

Although a few embodiments of the present general inventive concept havebeen shown and described, it will be appreciated by those skilled in theart that changes may be made in these embodiments without departing fromthe principles and spirit of the general inventive concept, the scope ofwhich is defined in the appended claims and their equivalents

1. A method of manufacturing an image sensor module, the methodcomprising: preparing an image sensor wafer that includes at least oneimage sensor and a bonding pad configured to receive a driving voltage;attaching a variable thickness member to the image sensor wafer, thevariable thickness member having a variable thickness along an opticalaxis of the light in accordance with the driving voltage; and forming alens wafer including at least one lens layer on the variable thicknessmember.
 2. The method of claim 1, wherein preparing the image sensorwafer comprises: forming an image sensor having the light receiver on asubstrate; forming a bonding pad on an edge portion of the substrate;and forming an electrode in the edge portion of the substrate toelectrically connect the bonding pad.
 3. The method of claim 1, whereinthe variable thickness member is attached to the image sensor wafer by athermo compression bonding process.
 4. The method of claim 1, whereinthe variable thickness member is attached to the image sensor wafer byan ultraviolet curing process.
 5. The method of claim 1, wherein thevariable thickness member comprises a conductive polymer having avariable volume in accordance with the driving voltage.
 6. The method ofclaim 5, wherein the conductive polymer comprises a piezoelectricmaterial.
 7. The method of claim 1, wherein: the image sensor wafercomprises a plurality of the image sensors; the lens wafer comprises theat least one lens layer; and the method further comprises: forming thelens wafer including the at least one lens layer on the variablethickness member; and cutting the lens wafer to form an image sensormodule including a single image sensor and a single lens layer.